Refrigeration



A. R. THOMAS REFRIGERATION May 2; 1944.

Filed May 6, 1941 4 Sheets-Sheet 1 INVENTOR y 1944- A. R. THOMAS2,347,757

REFRIGERATION Filed May 6, 1941 4 Sheets-Sheet 2 IN VENTOR MK/Vmu ATTORNE Y y 44- A. R. THOMAS 2,347,757

REFRIGERATION Filed May 6, 1941 4 Sheets-Sheet 3 7 a h 4 I 2 E 7 Z 47 vI INVENTOR A TTORNEYQ May 2, 1944.

A. R. THOMAS 2,347,757

REFRIGERATION Filed May 6, 1941 4 Sheets-Sheet 4 ATTORNEY Patented May2, 1944 REFRIGERATION Albert R. Thomas, Evansville, Ind., assignor toServe], Inc., New York, N. Y., a corporation of Delaware Application May6, 19h, Serial No. 392,090

4 Claims (Cl. 261-112) My invention relates to cooling towers, and moreparticularly to cooling towers of the induced draft type in which liquidflowing downward by gravity is cooledby partial evaporation into airflowing countercurrent to the liquid.

It is an object of my invention to provide an improved cooling tower inwhich air passes countercurrent to downwardly flowing liquid at arelatively high velocity with substantially no entrainment of liquid inthe air stream, so that the necessity of providing eliminators orsimilar devices to effect removal of liquid from the air stream isavoided.

Another object of the invention is to provide an improved cooling towerof the induced draft type in which counter-current flow of air andliquid is'efiected with air velocities as high as 1,000 feet per minute,so that a cooling tower of a given capacity will occupy a relativelysmall amountof space.

A further object of the invention is to provide an improved coolingtower in which the liquid to be cooled is distributed in a region orpocket not directly in the high velocity air stream to cause liquidfilms to be formed on suitable vertically extending surfaces contactedby the air stream.

A still further object of the invention is to provide an improvedcooling tower utilizing countercurrent flow of air and liquid to effectcooling of the liquid, and to spray the liquid onto the top edges ofpaneling at a region in which the air is relatively stagnant to produceliquid films adapted to be contacted by air flowing at a high velocity.

The novel features which I believe to be characteristic of my inventionare set forth with particularity in the claims. The invention, both asto organization and method, together with the above and other objectsand advantages thereof, will be better understood by reference to thefollowing description taken in connection with the manner in whichliquid films are formed on the paneling;

Fig. 5 is an enlarged fragmentary sectional view, taken on line 5-5 ofFig. 3; and

Figs. 6 and 7 are fragmentary perspective views illustrating in detailthe paneling shown in Figs. 3 and 4.

Referring to Fig. l, the improved cooling tower l0 embodying myinvention is shown in connection with an' absorption type refrigerationapparatus II. In apparatus of this type liquid refrigerant evaporates ina cooling unit with consequent absorption of heat from the surroundingsto produce a refrigeratinng effect. The refrigerant vapor formed in thecooling unit is absorbed into a liquid absorbent in an absorber l2 andabsorption liquid, enriched in refrigerant, is conducted to a generator.By heating the. generator, refrigerant is expelled from the absorptionliquid, liquefied in a condenser l4, and then returned to the coolingunit to complete the refrigerating cycle. In order to simplify thedrawings, the refrigeration apparatus illustrating a cooling towerembodying the invention shown in connection with an absorption typerefrigeration system;

Fig. 2 is a perspective view of the cooling tower shown in Fig. 1;

Fig. 3 is an enlarged vertical sectional view, taken on line 3-3 of Fig.2, to illustrate parts of the cooling tower more clearly;

Fig. 4 is an enlarged fragmentary sectional view, taken at line 4-4 ofFig. 3, to illustrate H has been illustrated very generally and inoutline with the absorber l2 and condenser 14 constituting the onlyparts specifically shown,

the remaining parts of the apparatus not being illustrated since this isnot believed to be necessary for an understanding of my invention.

The heat of absorption resulting from absorption of refrigerant vapor inabsorber I2 is given up to a suitable cooling liquid, such as water,which enters the absorber through a conduit IS. The cooling water isconducted from absorber l2 through a conduit I6 to condenser M in whichheat of condensation, resulting from condensation of refrigerant vapor,is given up to the cooling water. From the condenser l4 the coolingwater is conducted through a conduit I! to cooling tower I0, and, afterbeing cooled in the latter, the cooling water flows through conduit IEto absorber I2 to complete the cooling water cycle.

Referring more particularly to Figs. 1,2 and 3, the cooling tower It!includes a base l8, an upright shell l9 mounted on and extending upwardfrom the base l8, and a hood or cover 20; The base [8 is formed withinclined side walls 2| having air inlet openings 22 which are covered byscreens 23. One of the side walls of shell I9 is provided with anopening at the upper part of electrical energy." The motor 29 isdisposed in a casing 30 supported at the bottom of the horiz ontalportion of duct 24, and, in order to dampen the vibrations of the motor29, the latter is preferably mounted on rubber blocks, as indicated at3| in Fig. 3.

When fan 21 is operating, air is drawn into the base. l8 through theinlets 22 and flows upward through shell l9. The side wall of shell l9to which duct 24 is connected is provided with a deflector or baflie 32to increase the vertical distance through which air flows upwardly inshell I9, and also to causethe air to pass into the top part of thehorizontal portionof duct 24. From duct 24 the air is discharged at theoutlet 25 to the atmosphere. The screens 23 at the inlets 22 removeforeign matter from air drawn into the base i8, and the screen 26 at theoutlet 25 protects the fan 21 disposed in the duct 2d.

The cooling water conducted through conduit ll to the top part ofcooling tower ii] is distributed within the hood or cover 20 and flowsdownward by gravity in shell E9 in a manner to be described presently.During downward flow in shell it, the water is cooled by partialevaporation into the air stream flowing countercurrent thereto. Thecooled water collects in the bottom part of base it which serves as asump. To the base i8 is connected a conduit 33 through which water isconducted from a suitable source of supply. The water is maintained at apredetermined level in the bottom of base it by a float 34 operativelyconnected by an arm 35 to a valve 35 which is connected in the part ofconduit 33 within the base it.

During circulation of water in the cooling water circuit describedabove, a small amount of water is lost due to evaporation in the coolingtower iii. The water conducted to base l9 through conduit 33 keeps thewater at a predatermined level in the sump and is referred to asadditional or make-up water which takes the,

place of water lost by evaporation. An overflow conduit 31 is located inthe bottom part of base l8 so that water can flow to waste when theliquid level in the sump rises above the upper end of this conduit.

The water is drawn from the bottom of base l8 through suitable screening38 connected to the end of conduit i5, so that foreign matter will beremoved from the water prior to entering the absorber l2 and condenserM. A pump 39, which is connected in conduit i and arranged to be drivenin any suitable manner, as

ago

by an electric motor, for example, is provided to circulate the coolingwater through absorber l2 and condenser it of the refrigerationapparatus ll.

Within the upright shell l9 are disposed a plurality of closely spacedvertical panels ill. The panels fill are held in position by suitablesupporting structure including a plurality of horizontal angle membersii having the ends thereof secured to the end walls of base i8, asindicated at 42 in Fig. 3. The horizontal angle members 4| are locatedat the same height and are parallel to each other with each member beingdisposed adjacent to and substantially midway between the top and bottomedges of the inlets 22. To the horizontal angle members ii are securedthe lower ends of a plurality of U-shaped channels or guides 53, asshown most clearly in Figs.

3 and 5. The channels .23 are spaced close together at oppositesidewalls of shell it with the open ends' facing each other. The rearsides of the closed ends of channels 43 are secured to horizontal anglemembers 44 having the ends thereof connected to the end walls of shellH9. The horizontal angle members 45 are positioned at the extreme upperends and also at a central or intermediate region of the verticalchannels 43 to provide a rigid supporting structure for the panels sonow to be described more fully. A suitable reinforcing member 45 extendsfrom. one slopin sidewall 2i to the opposite sidewall of base it and isconnected at its ends to intermediate regions of the horizontal anglemembers 5! as best shown in Fig. 3.

The panels dd are preferably formed from a number of separate plates 56disposed one agove the other. The plates :55 may be formed of wood ormetal, and plates formed from red cypress have been satisfactorilyemployed. The vertical channels 33 at opposite sides of shell it aredirectly opposite each other and receive the plates so. The bottomplates dd of each panel ill rest directly against the bottom horizontalangle members 4!. From the base it to the region of shell 09 just belowthe top edge of deflector 32, the plates 46 in each'panel db preferablydo not abut each other but are spaced apart by approximately one-halfinch by spacer rods t? which are parallel to the-sidewalls and extendfrom one end wall to the opposite end wall of shell 59. The spacer rodsat rest against the open ends of vertical channels 33 with each rodbeing held in position by the weight of the plates lii and rods it aboveit. In'the top part of shell 99, at the region extending upward from theextreme top edge of deflector 32, the plates at rest directly againsteach other to form solid panel portions, as best shown in Figs. 3 and 4.

The hood or cover 29 is removably fastened to the top part of shell W,as indicated at at in Figs. 2 and 3. Within hood 2b is secured a pipe dbwhich serves as a manifold for distributing water and to which isconnected a plurality of spray heads or nozzles 5t. One end of the pipeat is closed and the other end thereof is open and passes through a wallin the hood 20, as shown in Fig. 4. To the part of pipe d9 extendingoutside the hood 2b is connected the lower end of conduit H. In orderthat the hood 28 can be readily removed during operation of the coolingtower, the lower portion of conduit ii is pref=- erably flexible.

The water conducted through conduit ill to the nozzles 5E5 is sprayed inthe pocket or chamber 59 formed by the hood 26. In order to form waterfilms on the panels to the top plates as of each panel are provided withwater distributing slats 52. The slats 52 are of the shape shown inFigs. 4 and 6 and are formed with tapered top portions to providesloping surfaces for conducting spray water toward the surfaces of thehighest plates 66'. The slats 52' are secured to the 'top plates co inany suitable manner, as indicated at 53 in Fig; 6. The slats 52 areformed with slots 52 to provide narrow passages at the surfaces ofplates 26 to facilitate the formation of the liquid films on thesurfaces of the panels ti.

During operation of the cooling tower it, the water returning from therefrigeration apparatus ii is sprayed into the chamber at by the nozzlesso, as described above. It is only necessary to deliver water to thenozzles 5d at a relatively oration into the upwardly flowing air.

low pressure which is just sufilcient to cause distribution of the waterover the entire top edges of the panels 40. In practice it has beenfound that delivering the water to the nozzles 50 at a pressure as lowas two or three pounds per square inch is adequate to producesatisfactory distribution of the water in chamber 5|.

The tapered sides of the slats 52 and adjacent surfaces of the uppermostplates 46 form troughs 55, as best shown in Fig. 4, in which watercollects. .The water collecting in the troughs 55 is formed by the dropsof spray. water falling onto the top edges of the uppermost plates 46and sloping sides of the slats 52. The water in troughs 55 passesbetween the contacting surfaces of the slats and portions of plates 46covered by the slats, and also around the ends of the slats and throughthe passages formed by the slots 54, to produce liquid films on all ofthe surfaces of the uppermost plates 46. The water films first flowcontinuously on the solid upper portions of the panels 40.

At the region just below the top edge of the deflector 32, the firstgaps 56 are formed in the panels by the uppermost spacer rods 41, asshown most clearly in Fig. 3. The gaps 56 are provided in the panels 40to cause the water to drip from the bottom edge of each plate 46 ontothe top edge of the succeeding lower plate to facilitate and promote thespreading of the water on the plates 46, so that the surfaces of thepanels 40 are completely wetted and the tendency for water films to'formdistinct streams will be avoided.

From the bottom edge of the lowermost plates 46 the water falls onto asplash plate 51 disposed in the base l8. The plate 51 is provided withinclined surfaces which are in the paths of the falling drops of liquidand extend below the water level in the base l8. With this arrangementthe water flows on the inclined surfaces of the plate 51 and eliminatesthe noise in splashing that is usually encountered when drops of waterfall onto the flat surface of a body of water.

The air drawn into the cooling tower I through the inlets 22 flows intothe passages between the panels 40 not only at the bottom edges of thepanels but also along the portions of the end edges thereof whichproject downward into the base l8 from the bottom of shell IS. The airflowing upward in shell H3 in the narrow passages between the panels 40acquires a high velocity and comes in contact with the films of waterformed on the surfaces of the plates 46. The Water flowing downward bygravity on the surfaces of the plates 46 is cooled by partial evap- Theair stream changes direction very abruptly at the top part of shell ISwith the air stream making practically a 90 or right angle turn fromshell I! into duct 24.

It will be seen that the distribution of water onto the top edges ofpanels 40 is effected n chamber 5| which forms a dead-end pocket in thetop part of the cooling tower with respect to the upwardly flowing airstream. The uppermost plates 46 and slats 52 associated therewithconstitute a barrier to flow of air into dead-end p cker, 5| in whichthe air is relatively stagnant. In this way the distribution of wateronto the panels 40 is effected in a region not directly in the highvelocity air stream flowing upward in shell l9 and passing into duct 24,as indicated by the arrows in Fig. 3. In the part of shell IS in whichthe high velocity air stream is passing. the air comes in contact withthe films of water which flow downward on and cling to the surfaces ofthe panels 40. The slats 52 insure the formation of the water films onthe panels 40, so that drops of water from chamber 5| will not fallbetween the panels 40 into the air passages.

Below the top edge of th deflector 32 drops of water fall in the gaps 56from the bottom edges of the plates 46 onto the top edges of thesucceeding lower plates. These drops of water fall in regions at oneside of streams of air passing upwardly at a relatively high velocitybetween the panels 46. The water dripping in the gaps 56 is protected toa great extent from the air flowing past the gaps from each plate 46 tothe succeeding higher plate. At the gaps 56 there is a tendency for thepressure at these regions to be reduced slightly due to the action ofthe high velocity air passing these regions, whereby a pulling effect isexerted on the drops of falling water. Since the pulling effect on thewater drops at one side of the gaps 56 is counteracted by a similarpulling effect on these drops at the opposite sides of the aps, thedrops of water in the gaps 56 tend to remain in these regions and fallonto the top edges of the plates 46. Hence, entrainment of the drops ofwater in gaps 56 by upwardly moving air is not readily effected.

At the upper region of shell I9 at which the air stream makes an abruptor right angle turn, the panels 40 are solid with no gaps providedbetween the individual plates 46. The solid portions of the panels 40provide continuous surfaces to which the water effectively clings, sothat entrainment of such water into the air stream is effectivelyprevented. Moreover, any tendency for water to be entrained in theupward- 1y air flowing in shell I9 is effectively counteracted by theabrupt change in direction of air flowing from the shell into the duct24.

The water dripping from the bottom edges of panels 40 onto thesplashplate 51 does not come into contact with high velocity air,because the air velocity does not build up until the air flows into thenarrow passages formed between the panels 40. Hence, there issubstantially no entrainment of water by the air While the latter ispassing through the upper part of base l8. Any tendency for water to beentrained in the air in base it is effectively counteracted by causingthe air stream to make an abrupt 90 or right angle turn upwardly intoshell I!) after entering the base 8 more or less horizontally throughthe the cooling tower at relatively high velocities is due primarily tospraying the water in the pocket or chamber 5| in which the air isrelatively stagnant, and flowing the water directly onto the surfaces ofthe panels 40 in the dead end pocket. With this arrangement, as pointedout above, when the water comes into contact with the upwardly flowingair stream, films of water are produced on the surfaces of the panels 40to which the water readily clings. By flowing air countercurrent tofllmsof water in the manner described, it is possible to effect coolingof water with their velocities as high as. 1,000 feet per minute,whereby a cooling tower of a given capacity will occupy a relativelysmall amount of space.

While a single embodiment of the invention has been shown and described,it will be apparent to those skilled in the art that modifications andchanges may be made without departing from the spirit and scope of theinvention,

as pointed out in the following claims.

What is claimed is:

1. A cooling tower comprising a casing providing an upright shaft havingan inlet for air in the lower part thereof and an outlet for air at theupper part thereof, members in said passage providing liquid bearingsurfaces projecting above said air outlet, liquid distribution structurefor depositing liquid on said surfaces and forming a liquid film thereonin a zone above said air outlet, said structure including a barrier toflow of air between the zone in which liquid is I deposited on saidsurfaces and said air outlet.

said liquid bearing surfaces being substantially continuous in verticalextent in the region of said air outlet so that all the liquid descendinby gravity through this region is adherent to said members so as not tobe entrained by air flowing from the passage at high velocity, and saidsurfaces having small gaps at places below said air outlet so thatliquid is redistributed on said surfaces by dripping across said gaps,the I spacing between said members being proportioned so that thevelocity of air is substantially the same on all sides of said gaps sothat the dripping liquid is not displaced into the air streams.

2. A cooling tower as set forth in claim 1 in which said liquiddistributing structure includes a spray device within a hood or coverremovably attached to said casing over the upper end of said shaft.

3. A cooling tower as in claim 1 in which said members are formed ofspaced apart vertically extending slats, and said liquid distributinstructure includes a sprayer over the upper ends of said slats, and saidbarrier is formed of closure members between adjacent slats, saidclosure members having drain openings adjacent the surfaces of theslats.

4. A cooling tower having a liquid inlet at the top, a filler comprisingspaced apart vertically extending slats, connections for flow of airupward through said tower, and a partition at the upper end of saidslats below said liquid inlet formed by a plurality of closure memberssecured between adjacent slats'at their upper ends to fill the gapsbetween said slats, said closure members having grooves in their edgesnext to the surfaces of said slats so that water deposited upon the topof said partition is divided by said closure members and flows downwardthrough said grooves at the opposite edges of said closure members on tothe opposing surfaces of each pair of adjacent slats.

ALBERT R. THOMAS.

